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iOS

Posted by Faraaz Khan
Faraaz Khan
1,091 Points

Dont understand repeat-while loops (Swift)

Hello Everyone,

I don't understand the difference between a repeat-while loop and a while loop. At the end of the day, they both do the same exact thing. Can someone please explain? Here is the code the video showed me how to write a loop:

var todo: [String] = ["Return Calls","Write Blogpost","Cook Dinner"]

var index = 0

while index < todo.count {
    print(todo[index])
    index++
}

index = 0

repeat {
    print(todo[index])
    index++
} while index < todo.count

1 Answer

Jhoan Arango
Jhoan Arango
14,575 Points

Hello :

Yes they do the same, but their difference is that one evaluates a condition first before performing any codes, and the other one performs the code and then continues to the evaluation.

This explanation comes from the e-book "The Swift Programming Language".

  • “A while loop starts by evaluating a single condition. If the condition is true, a set of statements is repeated until the condition becomes false.”

  • “The other variation of the while loop, known as the repeat-while loop, performs a single pass through the loop block first, before considering the loop’s condition. It then continues to repeat the loop until the condition is false.”

Faraaz Khan
Faraaz Khan
1,091 Points

Thank You so much! Explained it very well.